A man suspected of abducting a 5-year-old girl in Switzerland last week may have been involved in the murder of several other young people and links to the disappearance of Madeileine McCann are being investigated.
The body of Urs Hans Von Aesch (67) was found last Wednesday near the town of Appenzell, hours after Ylenia Lenhard (5) went missing in the town.
Police believe Von Aesch shot another man, who survived, before committing suicide.
Christof Kipfer, head of a commission that co-ordinates investigations of missing children, told Zurich's Tages Anzeigernewspaper that police were now trying to establish whether Von Aesch was involved in other abductions.
Police were re-examining the cases of eight young people, ranging in age from 5 to 16, who were either murdered or disappeared between 1982 and 1986, for possible links to Von Aesch, Mr Kipfer told the newspaper.
"All the children and adolescents disappeared from open streets, they are either still missing or were found dead. We can only see a rough pattern," Mr Kipfer was quoted saying.
Von Aesch recently returned to Switzerland after living in Spain for 17 years.
More than 100 troops were brought in today to help in the search for Ylenia. Police have been combing woods outside Appenzell but have so far found no trace of the girl who was last seen on seven days ago by her mother.
Mr Kipfer said Swiss authorities had been in touch with police investigating the disappearance in May of British 4-year-old Madeleine McCann. He declined to comment further.
A police spokesman in the Swiss town of St Gallen declined to comment on British media reports that investigators in Portugal were checking whether Von Aesch may have been in the area of Praia da Luz when Madeleine disappeared.